This section provides background information related to the present disclosure which is not necessarily prior art.
Vehicle-to-vehicle and vehicle-to-infrastructure (collectively referred to as V2X) safety technology relies on a host vehicle receiving messages via a dedicated short range communication (DSRC) system from at least one remote vehicle. DSRC technology relies heavily on Global Network Satellite Systems (GNSS) and Global Positioning Systems (GPS), along with Basic Safety Messages (BSM) periodically transmitted by vehicles containing the current vehicle position, position accuracy, speed, heading, brake status, and other vehicle information. With V2X technology, vehicles can have improved safety by knowing more about the other surrounding vehicles.
GNSS and GPS receivers claim to have a certain level of accuracy and often do in open-sky environments. For example, in open-sky environments, GNSS and GPS receivers achieve measurements within at least 1.5 meters (m) of accuracy. However, GNSS and GPS receivers are often less accurate in urban canyons such as cities that have very tall buildings, due to poor clear sky view and a high multi-path radio frequency (RF) signal environment. Unfortunately, the information provided from the GNSS and GPS receiver that is intended to indicate the level of accuracy does not always provide a good indication of the actual accuracy in the current situation. Some of the parameters used to provide GNSS and GPS accuracy within the National Marine Electronics Association (NMEA) 0183 standards include the Dilution of Precision information (horizontal dilution of precision—HDOP, vertical dilution of precision—VDOP, position dilution of precision—PDOP), error ellipse estimation information, and latitude/longitude error estimations. In some situations, the GNSS and GPS devices report an “accuracy” value that implies the position accuracy is better than the actual accuracy.
As such, there is a need to address the issue of accuracy in the GNSS and GPS systems. Improved safety can be achieved by ensuring that all V2X devices have an accurate understanding of the current GNSS and GPS accuracy in the given situation.